T-Mobile has just sent a new invitation for a press event on July 10, in New York City. While the carrier hasn't released what they plan to discuss during the event, they have mentioned that it will feature T-Mobile's "..boldest moves yet".Based on recent rumors and reports the assumption is that T-Mobile will unveil their UNcarrier Phase 2 plan, which would remove the need for a credit check when signing up for service.
This information is based on some recently leaked documents which suggest that T-Mobile has two major dates scheduled on their calendar. The first, which is on July 14, and labeled "Major EIT Release" could likely be what the carrier will announce on July 10.
The leaked reports also suggest that the Nokia Lumia 925 and the Sony Xperia Z are scheduled for launch through T-Mobile on July 17th, so its likely that the carrier will use July 10, to reveal more information on these device releases.
source - PhoneArena